TGFB1 and nasopharyngeal carcinoma: No association was observed between individual single nucleotide polymorphisms or their haplotypes and NPC susceptibility (for TGF-β1 C-509T: OR = 0.74; 95 % CI 0.46 − 1.18; for TGF-β1 T869C: OR = 0.86; 95 % CI 0.56 − 1.31), even when the samples were stratified by age, gender and TNM stage.